The present disclosure herein relates to a semiconductor memory device, and more particularly, to a semiconductor memory device with write operation characteristics and a method of operating the semiconductor memory device.
Generally, volatile memory devices such as Dynamic Random Access Memories (Hereinafter, referred to as DRAM) are accessed by a controller to perform a read operation or a write operation.
Since the distance between word lines, which selects the row direction of memory cells gets narrower due to the shrinkage of the DRAM manufacturing process, a further process shrinkage is physically facing a scaling limitation.
As a word line accessed gets closer to a word line adjacent thereto, the field coupling influence may increase. Accordingly, the fluctuation of a threshold voltage of an access transistor constituting a memory cell may get severe. When the threshold voltage of the access transistor becomes higher than a predetermined threshold voltage, the write operation characteristics of the DRAM, for example, tRDL (Last data-in to PRE command Period) parameter characteristics may become poor. Meanwhile, when the threshold voltage of the access transistor becomes lower than the predetermined threshold voltage due to the occurrence of a passing gate effect, the refresh operation characteristics of the DRAM may become worse.